1. Field of the Invention
The present invention relates to antennas for transmission and reception of radio frequency communications. More particularly to an antenna employing one or a plurality of planar radiator elements which are configured to extend the bandwidth in the lower frequencies of the wideband antenna. This extended lower frequency attenuation is enabled by using notched edges to yield a slow wave structure to the narrowing cavity of the element. The device is especially well adapted for broadband communications using the disclosed radiator elements which are employable individually or engageable to other similarly configured antenna elements with stepped edges allowing for an increase in the bandwith of the formed element.
2. Prior Art
Conventionally, cellular, radio, and television antennas are formed in a structure that may be adjustable for frequency and gain by changing the formed structure elements. Shorter elements are used for higher frequencies, longer elements for lower, and pluralities of similarly configured shorter and longer elements are used to increase gain or steer the beam. Such elements are conventionally dipole elements either fixed to a Yagi style antenna, rabbit ears, or other configurations.
However, a conventional formed antenna structure or node itself is generally fixed in position but for the dipole or other style radiator elements which may be adjusted for length or angle to better transmit and receive on narrow band frequencies of choice in a location of choice to serve certain users of choice.
With modern communications enabling more use of more and more areas of the RF spectrum, many communications firms employ many different frequencies, for many different types of communications and devices. The result being that many different such individual antenna towers are required due to the plurality of providers, and the plurality of different frequencies of each provider and/or each type of communication. The results in one and generally a plurality of such towers, each having dipole or other radiator elements upon them, in sizes to match the individual frequencies employed by the provider for different services such as WiFi, television, or cellular phones or police radios. This frequently results in multiple such antenna towers, within yards of each other, on hills, or other high points servicing surrounding areas. Such duplication of effort is not only expensive but tends to be an eyesore in the community.
Conventionally, when constructing a communications array such as a cellular antenna grid or a wireless communications web, the builder is faced with the dilemma. The plurality of different frequencies for the different RF bands require the obtaining of multiple antennas which are customized by antenna providers for the narrow frequency to be serviced. Most such antennas are custom made using dipole type radiator elements to match the narrow band of frequencies to be employed at the site which can vary widely depending on the network and venue.
The problem for the site builder and operator is further complicated if a horizontal, vertical, or circular RF polarization scheme is desired to either increase bandwidth or available connections. Further consideration must be given to the gain at the chosen frequency and thereafter the numbers elements included in the final structure to meet the gain requirements and possible beam steering requirements.
However, such antennas, once manufactured to specific individual frequencies or narrow frequency bands, offer little means of adjustment of their final frequency range and their gain since they are generally fixed in nature. Further, since they are custom manufactured to the frequency band, gain, polarization, beam width, and other requirements, should technology change or new frequencies become available, it can be a problem since new antennas are required to match the changes.
Still further, for a communications system provider, working on many different bands with many frequencies in differing wireless cellular or grid communications schemes, a great deal of inventory of the various antennas for the plurality of frequencies employed at the desired gains and polarization schemes must be maintained. Without stocking a large inventory of antennas, delays in installation can occur. Such an inventory requirement increases costs tremendously as well as deployment lead time if the needed antenna configuration is not at hand.
Additionally, during installation, it is hard to predict the required final antenna construction configuration since in a given topography, what works on paper may not work in the field. This is further complicated should exact gain and polarization or frequency range which may be required for a given system being installed, should it not match predictions. The result being that a delay will inherently occur where custom antennas must be manufactured for the user if they are not stocked.
This is especially true in cases where a wireless grid or web is being installed for wireless communications such as radios, internet, or cell phones. The frequencies can vary widely depending on the type of wireless communications being implemented in the grid, such as cellular or WiFi or digital communications for emergency services. The system requirements for gain and individual employed frequencies can also vary depending on the FCC and client's needs.
Still further, the infrastructure required for conventional commercial broadcast and receiving cellular, radio and other antennas, require that each antenna at each site, be hard-wired to the local communications grid. This not only severely limits the location of individual antenna nodes in such a grid, it substantially increases the costs since each antenna services a finite number of users and it must be hardwired to a local network on the ground.
As such, there is a continuing unmet need for an improved antenna element, providing an improved device and method of antenna tower or node construction, allowing for easy formation and configuration of a radio antenna for two way communications such as cellular or radio for police or emergency services. Such a device would be best if modular in nature and employ individual radiator elements which provide a very high potential for the as-needed configuration for specific frequency gain, frequency rejection, polarization, direction, steering and other factors desired, in an antenna grid servicing multiple but varying numbers of users over a day's time.
Such a device should employ wideband antenna elements allowing for a maximizing of both transmission and receipt of communications between a high and low frequency limit of the element. The components, so assembled, should provide electrical pathways electrically communicated in a standardized connection to transceivers. Such a device should employ a single antenna element capable of providing for a wide range of different frequencies to be transmitted and received. Such a device, by using a plurality of individual antenna elements of substantially identical construction, should be switchable in order to increase or decease gain and steer the individual communications beams.
Employing a plurality of individual wideband antenna elements, such a device should enable the capability of forming antenna sites using a kit of individual antenna element components, each of which are easily engageable with the base components. These individual antenna element components should have electrical pathways which easily engage those of the base components of the formed antenna to allow for snap-together or other easy engagement to the base components hosting the antenna elements. Such a device should be capable of concurrently achieving a switchable electrical connection from each of the individual antenna elements across the base components and to the transceiver in communication with one or a plurality of the antenna elements.